The Milk Thistle (Silybum marianum) Compound Silibinin Inhibits Cardiomyogenesis of Embryonic Stem Cells by Interfering with Angiotensin II Signaling

Figure 3

Effects of Ang II and silibinin on the frequency of Ca²⁺ transients in cardiac cells differentiated from ES cells. Cardiac cells were enzymatically dissociated from 7-day-old embryoid bodies and labeled on day 8 with the Ca²⁺-sensitive fluorescence dye Fluo-4. Ca²⁺ spiking was evaluated in 3 different time windows, i.e., 200 s, 600 s, and 1500 s. Shown are representative traces of individual cells. (a) Untreated controls, (b) silibinin- (20 μM) treated cells, (c) Ang II- (1 μM) treated cells, and (d) cells treated with a combination of Ang II (1 μM) and silibinin (20 μM). The bar chart in (e) shows the means ± S.D. of 10 experiments. , significantly different to the untreated control. , significantly different to the Ang II-treated sample. (f) Representative Ca²⁺ transients in rat smooth muscle cells. Upper panel: cells were treated with Ang II (1 μM) and changes in Fluo-4 fluorescence were recorded. Bottom panel: cells were preincubated for 60 min with silibinin (20 μM) and subsequently treated with Ang II (1 μM) ().